[Efficacy analysis of autologous facet joint bone block in lumbar interbody fusion of osteoporosis patients].

OBJECTIVE: To compare and analyze the feasibility of autologous facet joint bone block as an alternative to polyetheretherketone (PEEK) cage in lumbar intervertebral fusion surgery for patients with osteoporosis. METHODS: From December 2018 to June 2021, the case data of patients with osteoporosis (T value ≤ -2.5 on dual energy X-ray bone density) who underwent posterior lumbar interbody fusion in the Fourth Medical Center, Chinese PLA General Hospital were retrospectively reviewed. All the cases were followed up for no less than 12 months and were divided into two groups according to the differences of interbody fusion materials: the autologous facet joint bone block group (autogenous bone group) and the PEEK cage group (PEEK group). The general data [such as age, gender, body mass index (BMI), primary diagnosis, distribution of fusion segments, bone mineral density of lumbar (BMD), incidence of preoperative complications], the perioperative data (such as duration of operation, intraoperative blood loss, postoperative drainage, perioperative allogeneic blood transfusion rate), and the incidence of postoperative complications were compared between the two groups. Imaging parameters (disc height, lumbar lordosis angle, segment lordosis angle, segmental lordosis angle, disc height improvement rate, and fusion rate) and lumbar functional scores [visual analogue scale (VAS), Oswestry disability index (ODI), Japanese Orthopedics Association (JOA) score for lower back pain] were compared to evaluate the clinical efficacy between the kinds of intervertebral fusion materials 1 week, 3 months and 6 months postoperative and at the last follow-up. RESULTS: A total of 118 patients were enrolled, including 68 cases in the autogenous bone group and 50 cases in the PEEK group, there were no statistical differences in age, gender, BMI, primary diagnosis, distribution of fusion segments, BMD, incidence of preoperative complications, duration of operation, intraoperative blood loss, postoperative drainage, perioperative allogeneic blood transfusion rate, incidence of postoperative complications, all the preoperative imaging parameters and all the lumbar function scores between the two groups (P>0.05). Postoperative superficial surgical site infections occurred in 3 patients in the autogenous bone group and 2 patients in the PEEK group. At the last follow-up, 3 cases of intervertebral graft collapse occurred in the autogenous bone group and 5 cases in the PEEK group, 1 case of graft subsidence in the autogenous bone group and 1 case in the PEEK group. All the imaging parameters showed significant differences between postoperation and preoperation (P < 0.05), and all the imaging parameters showed significant differences between 1 week and 3 months postoperative in both groups (P < 0.05). The height, angle of fusion gap in the autogenous bone group were lower than those in the PEEK group 1 week postoperatively (P < 0.05), and the fusion gap height improvement rate in the autogenous bone group was lower than that in the PEEK group (P < 0.05). The cases in both groups started to show final fusion 3 months after surgery, and the fusion rate in the autogenous bone group was 75% 6 months postoperatively, which was significantly higher than the rate of 56% in the PEEK group (P < 0.05), and there was no statistically significant difference in the final fusion rate between the two groups (P>0.05). The ODI, the postoperative VAS score was significantly lower than that in preoperation, while the postoperative JOA score was significantly higher than that in preoperation (P < 0.05). The ODI was lower while the JOA score was higher of the autogenous bone group than that of the PEEK group 6 months postoperatively (P < 0.05). CONCLUSION: In osteoporosis patients, good interbody fusion rate and improvement of lumbar vertebral function can be obtained by using autologous facet joint bone block or PEEK cage, while the fusion rate and the improvement of lumbar function with autologous facet joint bone block are better than those with PEEK cage 6 months post-operatively. PEEK cage is superior to autologous facet joint bone block in intervertebral distraction and improvement of lumbar lordosis. Significant disc space subsidence occurred in osteoporotic patients within 3 months after lumbar interbody fusion, and the subsidence of PEEK cage was more obvious than that of autologous facet joint bone block.

Ghrelin infusion into the basolateral amygdala suppresses CTA memory formation in rats via the PI3K/Akt/mTOR and PLC/PKC signaling pathways.

Ghrelin is a circulating orexigenic hormone that promotes feeding behavior and regulates metabolism in humans and rodents. We previously reported that local infusion of ghrelin into the basolateral amygdala (BLA) blocked memory acquisition for conditioned taste aversion (CTA) by activating growth hormone secretagogue receptor 1a. In this study, we further explored the underlying mechanism and signaling pathways mediating ghrelin modulation of CTA memory in rats. Pharmacological agents targeting distinct signaling pathways were infused into the BLA during conditioning. We showed that preadministration of the PI3K inhibitor LY294002 abolished the repressive effect of ghrelin on CTA memory. Moreover, LY294002 pretreatment prevented ghrelin from inhibiting Arc and zif268 mRNA expression in the BLA triggered by CTA memory retrieval. Preadministration of rapamycin eliminated the repressive effect of ghrelin, while Gsk3 inhibitors failed to mimic ghrelin's effect. In addition, PLC and PKC inhibitors microinfused in the BLA blocked ghrelin's repression of CTA acquisition. These results demonstrate that ghrelin signaling in the BLA shapes CTA memory via the PI3K/Akt/mTOR and PLC/PKC pathways. We conducted in vivo multichannel recordings from mouse BLA neurons and found that microinjection of ghrelin (20 µM) suppressed intrinsic excitability. By means of whole-cell recordings from rat brain slices, we showed that bath application of ghrelin (200 nM) had no effect on basal synaptic transmission or synaptic plasticity of BLA pyramidal neurons. Together, this study reveals the mechanism underlying ghrelin-induced interference with CTA memory acquisition in rats, i.e., suppression of intrinsic excitability of BLA principal neurons via the PI3K/Akt/mTOR and PLC/PKC pathways.

Urokinase-Type Plasminogen Activator Protects Cerebral Cortical Neurons from Soluble Aß-Induced Synaptic Damage.

Soluble amyloid ß (Aß)-induced synaptic dysfunction is an early event in the pathogenesis of Alzheimer's disease (AD) that precedes the deposition of insoluble Aß and correlates with the development of cognitive deficits better than the number of plaques. The mammalian plasminogen activation (PA) system catalyzes the generation of plasmin via two activators: tissue-type (tPA) and urokinase-type (uPA). A dysfunctional tPA-plasmin system causes defective proteolytic degradation of Aß plaques in advanced stages of AD. In contrast, it is unknown whether uPA and its receptor (uPAR) contribute to the pathogenesis of this disease. Neuronal cadherin (NCAD) plays a pivotal role in the formation of synapses and dendritic branches, and Aß decreases its expression in cerebral cortical neurons. Here we show that neuronal uPA protects the synapse from the harmful effects of soluble Aß. However, Aß-induced inactivation of the eukaryotic initiation factor 2α halts the transcription of uPA mRNA, leaving unopposed the deleterious effects of Aß on the synapse. In line with these observations, the synaptic abundance of uPA, but not uPAR, is decreased in the frontal cortex of AD patients and 5xFAD mice, and in cerebral cortical neurons incubated with soluble Aß. We found that uPA treatment increases the synaptic expression of NCAD by a uPAR-mediated plasmin-independent mechanism, and that uPA-induced formation of NCAD dimers protects the synapse from the harmful effects of soluble Aß oligomers. These data indicate that Aß-induced decrease in the synaptic abundance of uPA contributes to the development of synaptic damage in the early stages of AD.SIGNIFICANCE STATEMENT Soluble amyloid ß (Aß)-induced synaptic dysfunction is an early event in the pathogenesis of cognitive deficits in Alzheimer's disease (AD). We found that neuronal urokinase-type (uPA) protects the synapse from the deleterious effects of soluble Aß. However, Aß-induced inactivation of the eukaryotic initiation factor 2α decreases the synaptic abundance of uPA, leaving unopposed the harmful effects of Aß on the synapse. In line with these observations, the synaptic expression of uPA is decreased in the frontal cortex of AD brains and 5xFAD mice, and uPA treatment abrogates the deleterious effects of Aß on the synapse. These results unveil a novel mechanism of Aß-induced synaptic dysfunction in AD patients, and indicate that recombinant uPA is a potential therapeutic strategy to protect the synapse before the development of irreversible brain damage.

Neovascularization and tissue regeneration by endothelial progenitor cells in ischemic stroke.

Endothelial progenitor cells (EPCs) are immature endothelial cells (ECs) capable of proliferating and differentiating into mature ECs. These progenitor cells migrate from bone marrow (BM) after vascular injury to ischemic areas, where they participate in the repair of injured endothelium and new blood vessel formation. EPCs also secrete a series of protective cytokines and growth factors that support cell survival and tissue regeneration. Thus, EPCs provide novel and promising potential therapies to treat vascular disease, including ischemic stroke. However, EPCs are tightly regulated during the process of vascular repair and regeneration by numerous endogenous cytokines that are associated closely with the therapeutic efficacy of the progenitor cells. The regenerative capacity of EPCs also is affected by a range of exogenous factors and drugs as well as vascular risk factors. Understanding the functional properties of EPCs and the factors related to their regenerative capacity will facilitate better use of these progenitor cells in treating vascular disease. Here, we review the current knowledge of EPCs in cerebral neovascularization and tissue regeneration after cerebral ischemia and the factors associated with their regenerative function to better understand the underlying mechanisms and provide more effective strategies for the use of EPCs in treating ischemic stroke.

Cell-type specific deletion of GABA(A)α1 in corticotropin-releasing factor-containing neurons enhances anxiety and disrupts fear extinction.

Corticotropin-releasing factor (CRF) is critical for the endocrine, autonomic, and behavioral responses to stressors, and it has been shown to modulate fear and anxiety. The CRF receptor is widely expressed across a variety of cell types, impeding progress toward understanding the contribution of specific CRF-containing neurons to fear dysregulation. We used a unique CRF-Cre driver transgenic mouse line to remove floxed GABA(A)α1 subunits specifically from CRF neurons [CRF-GABA(A)α1 KO]. This process resulted in mice with decreased GABA(A)α1 expression only in CRF neurons and increased CRF mRNA within the amygdala, bed nucleus of the stria terminalis (BNST) and paraventricular nucleus of the hypothalamus. These mice show normal locomotor and pain responses and no difference in depressive-like behavior or Pavlovian fear conditioning. However, CRF-GABA(A)α1 KO increased anxiety-like behavior and impaired extinction of conditioned fear, coincident with an increase in plasma corticosterone concentration. These behavioral impairments were rescued with systemic or BNST infusion of the CRF antagonist R121919. Infusion of Zolpidem, a GABA(A)α1-preferring benzodiazepine-site agonist, into the BNST of the CRF-GABA(A)α1 KO was ineffective at decreasing anxiety. Electrophysiological findings suggest a disruption in inhibitory current may play a role in these changes. These data indicate that disturbance of CRF containing GABA(A)α1 neurons causes increased anxiety and impaired fear extinction, both of which are symptoms diagnostic for anxiety disorders, such as posttraumatic stress disorder.

Genetic ablation of receptor for advanced glycation end products promotes functional recovery in mouse model of spinal cord injury.

Spinal cord injury (SCI) results in a loss of normal motor and sensory function, leading to severe disability and reduced quality of life. The aim of this work was to investigate the effect of receptor for advanced glycation end products (RAGE) deficiency on the function recovery in a mouse model of SCI. Mice received a mid-thoracic spinal contusion injury. Upregulation of RAGE protein expression in spinal cord tissue was evident at 12 h after SCI and continued at 2 and 5 days. Furthermore, we showed that locomotor recovery was improved and lesion pathology was reduced after SCI in RAGE-deficient mice. RAGE deficiency in mice attenuated apoptosis after SCI through inhibiting p53/Bax/caspase-3 pathway. RAGE deficiency in mice inhibited inflammation after SCI, marked by reduced myeloperoxidase activity, NFκB nuclear translocation, and TNF-α, IL-1ß, and IL-6 mRNA and protein levels. RAGE deficiency in mice exposed to SCI suppressed the upregulation of inducible nitric oxide synthase (iNOS) and gp91-phox and attenuated oxidative and nitrosative stresses, marked by reduced formation of malondialdehyde, reactive oxygen species, peroxynitrite (OONO(-)), and 3-nitrotyrosine. RAGE deficiency in mice exposed to SCI attenuated glial scar at the injury site, marked by decreased expression of glial fibrillary acidic protein. These data indicate that the RAGE plays an important role in the development of SCI and might provide a therapeutic target to promote recovery from SCI.

Postnatal maturation of GABAergic transmission in the rat basolateral amygdala.

Many psychiatric disorders, including anxiety and autism spectrum disorders, have early ages of onset and high incidence in juveniles. To better treat and prevent these disorders, it is important to first understand normal development of brain circuits that process emotion. Healthy and maladaptive emotional processing involve the basolateral amygdala (BLA), dysfunction of which has been implicated in numerous psychiatric disorders. Normal function of the adult BLA relies on a fine balance of glutamatergic excitation and GABAergic inhibition. Elsewhere in the brain GABAergic transmission changes throughout development, but little is known about the maturation of GABAergic transmission in the BLA. Here we used whole cell patch-clamp recording and single-cell RT-PCR to study GABAergic transmission in rat BLA principal neurons at postnatal day (P)7, P14, P21, P28, and P35. GABAA currents exhibited a significant twofold reduction in rise time and nearly 25% reduction in decay time constant between P7 and P28. This corresponded with a shift in expression of GABAA receptor subunit mRNA from the α2- to the α1-subunit. The reversal potential for GABAA receptors transitioned from depolarizing to hyperpolarizing with age, from around -55 mV at P7 to -70 mV by P21. There was a corresponding shift in expression of opposing chloride pumps that influence the reversal, from NKCC1 to KCC2. Finally, we observed short-term depression of GABAA postsynaptic currents in immature neurons that was significantly and gradually abolished by P28. These findings reveal that in the developing BLA GABAergic transmission is highly dynamic, reaching maturity at the end of the first postnatal month.

Developmental pyrethroid exposure causes a neurodevelopmental disorder phenotype in mice.

Neurodevelopmental disorders (NDDs) are a widespread and growing public health challenge, affecting as many as 17% of children in the United States. Recent epidemiological studies have implicated ambient exposure to pyrethroid pesticides during pregnancy in the risk for NDDs in the unborn child. Using a litter-based, independent discovery-replication cohort design, we exposed mouse dams orally during pregnancy and lactation to the Environmental Protection Agency's reference pyrethroid, deltamethrin, at 3 mg/kg, a concentration well below the benchmark dose used for regulatory guidance. The resulting offspring were tested using behavioral and molecular methods targeting behavioral phenotypes relevant to autism and NDD, as well as changes to the striatal dopamine system. Low-dose developmental exposure to the pyrethroid deltamethrin (DPE) decreased pup vocalizations, increased repetitive behaviors, and impaired both fear conditioning and operant conditioning. Compared with control mice, DPE mice had greater total striatal dopamine, dopamine metabolites, and stimulated dopamine release, but no difference in vesicular dopamine capacity or protein markers of dopamine vesicles. Dopamine transporter protein levels were increased in DPE mice, but not temporal dopamine reuptake. Striatal medium spiny neurons showed changes in electrophysiological properties consistent with a compensatory decrease in neuronal excitability. Combined with previous findings, these results implicate DPE as a direct cause of an NDD-relevant behavioral phenotype and striatal dopamine dysfunction in mice and implicate the cytosolic compartment as the location of excess striatal dopamine.

A transcriptomic analysis of type I-III neurons in the bed nucleus of the stria terminalis.

The activity of neurons in the anterolateral cell group of the bed nucleus of the stria terminalis (BNST(ALG)) plays a critical role in anxiety- and stress-related behaviors. Histochemical studies have suggested that multiple distinct neuronal phenotypes exist in the BNST(ALG). Consistent with this observation, the physiological properties of BNST(ALG) neurons are also heterogeneous, and three distinct cell types can be defined (Types I-III) based primarily on their expression of four key membrane currents, namely I(h), I(A), I(T), and I(K(IR)). Significantly, all four channels are multimeric proteins and can comprise of more than one pore-forming α subunit. Hence, differential expression of α subunits may further diversify the neuronal population. However, nothing is known about the relative expression of these ion channel α subunits in BNST(ALG) neurons. We have addressed this lacuna by combining whole-cell patch-clamp recording together with single-cell reverse transcriptase polymerase chain reaction (scRT-PCR) to assess the mRNA transcript expression for each of the subunits for the four key ion channels in Type I-III neurons of the BNST(ALG.) Here, cytosolic mRNA from single neurons was probed for the expression of transcripts for each of the α subunits of I(h) (HCN1-HCN4), I(T) (Ca(v)3.1-Ca(v)3.3), I(A) (K(v)1.4, K(v)3.4, K(v)4.1-K(v) 4.3) and I(K(IR)) (Kir2.1-Kir2.4). An unbiased hierarchical cluster analysis followed by discriminant function analysis revealed that a positive correlation exists between the physiological and genetic phenotype of BNST(ALG) neurons. Thus, the analysis segregated BNST(ALG) neurons into 3 distinct groups, based on their α subunit mRNA expression profile, which positively correlated with our existing electrophysiological classification (Types I-III). Furthermore, analysis of mRNA transcript expression in Type I-Type III neurons suggested that, whereas Type I and III neurons appear to represent genetically homologous cell populations, Type II neurons may be further subdivided into three genetically distinct subgroups. These data not only validate our original classification scheme, but further refine the classification at the molecular level, and thus identifies novel targets for potential disruption and/or pharmacotherapeutic intervention in stress-related anxiety-like behaviors.

Social experience alters oxytocinergic modulation in the nucleus accumbens of female prairie voles.

Social relationships are dynamic and evolve with shared and personal experiences. Whether the functional role of social neuromodulators also evolves with experience to shape the trajectory of relationships is unknown. We utilized pair bonding in the socially monogamous prairie vole as an example of socio-sexual experience that dramatically alters behaviors displayed toward other individuals. We investigated oxytocin-dependent modulation of excitatory synaptic transmission in the nucleus accumbens as a function of pair-bonding status. We found that an oxytocin receptor agonist decreases the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) in sexually naive virgin, but not pair-bonded, female voles, while it increases the amplitude of electrically evoked EPSCs in paired voles, but not in virgins. This oxytocin-induced potentiation of synaptic transmission relies on the de novo coupling between oxytocin receptor signaling and endocannabinoid receptor type 1 (CB1) receptor signaling in pair-bonded voles. Blocking CB1 receptors after pair-bond formation increases the occurrence of a specific form of social rejection-defensive upright response-that is displayed toward the partner, but not toward a novel individual. Altogether, our results demonstrate that oxytocin's action in the nucleus accumbens is changed through social experience in a way that regulates the trajectory of social interactions as the relationship with the partner unfolds, potentially promoting the maintenance of a pair bond by inhibiting aggressive responses. These results provide a mechanism by which social experience and context shift oxytocinergic signaling to impact neural and behavioral responses to social cues.

[Comparison of the grafting technique in treatment of thoracolumbar burst fractures:transpedicular intracorporeal versus posterolateral].

OBJECTIVES: To retrospectively investigate the outcome of transpedicular intracorporeal grafting and posterolateral grafting in treatment of thoracolumbar burst fractures. METHODS: Forty-six patients treated with transpedicular intracorporeal grafting from January 1999 to December 2009 and followed up for 19-119 months (average 67 ± 13 months) were reviewed retrospectively, and were compared with 18 patients who had underwent posterolateral fusion during the same period through radiographic analysis. Radiographic measurements included Cobb angle, vertebral wedge angle (VWA), ratio between anterior and posterior vertebral height (APHR), upper inter-vertebral angle, lower inter-vertebral angle on X-ray, CT and MRI. RESULTS: In transpedicular intracorporeal grafting group, the VWA was corrected from 27.2° ± 6.5° to 7.0° ± 3.0° and the APHR from (53.3 ± 11.8)% to (92.3 ± 2.4)%. In posterolateral fusion group, the VWA was corrected from 23.9° ± 4.4° to 8.8° ± 2.1° and the APHR from (60.7 ± 10.0)% to (88.5 ± 3.3)%. Transpedicular intracorporeal grafting group showed better postoperative correction results than posterolateral fusion group (P < 0.05), and had less loss of correction of Cobb angle, VWA and APHR at final follow-up (P < 0.05). CONCLUSIONS: The transpedicular intracorporeal grafting can improve injured vertebral body morphology recovery better than posterolateral bone grafting, but can not prevent the late loss of correction after implant removal.

Damage to dopaminergic neurons by oxidative stress in Parkinson's disease (Review).

Oxidative stress is increasingly recognized as a central event contributing to the degeneration of dopaminergic neurons in the pathogenesis of Parkinson's disease (PD). Although reactive oxygen species (ROS) production is implicated as a causative factor in PD, the cellular and molecular mechanisms linking oxidative stress with dopaminergic neuron death are complex and not well characterized. The primary insults cause the greatest production of ROS, which contributes to oxidative damage by attacking all macromolecules, including lipids, proteins and nucleic acids, leading to defects in their physiological function. Consequently, the defects in these macromolecules result in mitochondrial dysfunction and neuroinflammation, which subsequently enhance the production of ROS and ultimately neuronal damage. The interaction between these various mechanisms forms a positive feedback loop that drives the progressive loss of dopaminergic neurons in PD, and oxidative stress­mediated neuron damage appears to serve a central role in the neurodegenerative process. Thus, understanding the cellular and molecular mechanisms by which oxidative stress contributes to the loss of dopaminergic neurons may provide a promising therapeutic approach in PD treatment.

Group II metabotropic glutamate receptors in anxiety circuitry: correspondence of physiological response and subcellular distribution.

Activation of group II metabotropic glutamate receptors (mGluR2/3) in the amygdala plays a critical role in the regulation of fear and anxiety states. Previous studies using nonselective agonists have suggested this action can result from activation of either pre- or postsynaptic mGluR2/3. Here, we have used a combination of whole-cell patch clamp recording with highly selective agonists (LY354740 and LY379268) and immunoelectron microscopy to examine structure-function relationships for mGluR2/3 in the basolateral amygdala (BLA) and bed nucleus of the stria terminalis (BNST). Stimulation of mGluR2/3 evoked a direct, TTX-insensitive membrane hyperpolarization in all BLA projection neurons tested, but only about half of BNST neurons. The membrane hyperpolarization was mediated by activation of an outward potassium current or blockade of a tonically active inward I(h) current in different groups of BLA neurons. In both regions, mGluR2/3 caused a long-lasting reduction of glutamate release from presynaptic afferent terminals even at concentrations that failed to elicit a direct postsynaptic response. The localization of mGluR2/3 differed regionally, with postsynaptic labeling significantly more common in BLA than BNST, corresponding to the strength of postsynaptic responses recorded there. Our results demonstrate a complex role for mGluR2/3 receptors in modulating anxiety circuitry, including direct inhibition and reduction of excitatory drive. The combination of direct inhibition of projection neurons within the BLA and suppression of excitatory neurotransmission in the BNST may be responsible for the anxiolytic actions of group II mGluR agonists.

[Diagnosis and surgical treatment of back pain originating from endplate].

OBJECTIVE: To explore the methods of diagnosis and surgical treatment for patients with back pain originating from endplate. METHODS: All patients received examinations of radiography, CT, and MR imaging. Pain level of disc was decided by discography in each patient. The principal outcome judgment were pain and disability, and the efficacy of surgical treatment was assessed by visual analog scale (VAS) for pain, and the Oswestry disability index (ODI) for functional recovery. RESULTS: All patients with a diagnosis of back pain originating from endplate according to discography were treated with anterior or posterior fusion surgery. The mean follow-up period was three years and five months (from 2 to 6 years). Among of the 21 patients, 20 (95%) reported a disappearance or marked alleviation of low back pain, and experienced a definite improvement in physical function. A statistically significant and clinically meaningful improvement on the ODI and the VAS scores were obtained in the patients with chronic low back pain originating from endplate (P = 0.0001) after treatment. CONCLUSIONS: The study suggests that the discography and fusion surgery may be very effective methods for the diagnosis and treatment of chronic back pain originating from endplate respectively.

Serotonin gating of cortical and thalamic glutamate inputs onto principal neurons of the basolateral amygdala.

The basolateral amygdala (BLA) is a key site for crossmodal association of sensory stimuli and an important relay in the neural circuitry of emotion. Indeed, the BLA receives substantial glutamatergic inputs from multiple brain regions including the prefrontal cortex and thalamic nuclei. Modulation of glutamatergic transmission in the BLA regulates stress- and anxiety-related behaviors. Serotonin (5-HT) also plays an important role in regulating stress-related behavior through activation of both pre- and postsynaptic 5-HT receptors. Multiple 5-HT receptors are expressed in the BLA, where 5-HT has been reported to modulate glutamatergic transmission. However, the 5-HT receptor subtype mediating this effect is not yet clear. The aim of this study was to use patch-clamp recordings from BLA neurons in an ex vivo slice preparation to examine 1) the effect of 5-HT on extrinsic sensory inputs, and 2) to determine if any pathway specificity exists in 5-HT regulation of glutamatergic transmission. Two independent input pathways into the BLA were stimulated: the external capsule to mimic cortical input, and the internal capsule to mimic thalamic input. Bath application of 5-HT reversibly reduced the amplitude of evoked excitatory postsynaptic currents (eEPSCs) induced by stimulation of both pathways. The decrease was associated with an increase in the paired-pulse ratio and coefficient of variation of eEPSC amplitude, suggesting 5-HT acts presynaptically. Moreover, the effect of 5-HT in both pathways was mimicked by the selective 5-HT1B receptor agonist CP93129, but not by the 5-HT1A receptor agonist 8-OH DPAT. Similarly the effect of exogenous 5-HT was blocked by the 5-HT1B receptor antagonist GR55562, but not affected by the 5-HT1A receptor antagonist WAY 100635 or the 5-HT2 receptor antagonists pirenperone and MDL 100907. Together these data suggest 5-HT gates cortical and thalamic glutamatergic inputs into the BLA by activating presynaptic 5-HT1B receptors.

Amygdala-Dependent Molecular Mechanisms of the Tac2 Pathway in Fear Learning.

Recently we determined that activation of the tachykinin 2 (Tac2) pathway in the central amygdala (CeA) is necessary and sufficient for the modulation of fear memories. The Tac2 pathway includes the Tac2 gene, which encodes the neuropeptide neurokinin B and its corresponding receptor neurokinin 3 receptor (NK3R). In this study, using Tac2-cre and Tac2-GFP mice, we applied a combination of in vivo (optogenetics) and multiple in vitro techniques to further explore the mechanisms of action within the Tac2 pathway. In transgenic mice that express ChR2 solely in Tac2 neurons, in vivo optogenetic stimulation of CeA Tac2-expressing neurons during fear acquisition enhanced fear memory consolidation and drove action potential firing in vitro. In addition, Tac2-CeA neurons were shown to co-express striatal-enriched protein tyrosine phosphatase, which may have an important role in regulating Nk3R signaling during fear conditioning. These data extend our current understanding for the underlying mechanism(s) for the role of the Tac2 pathway in the regulation of fear memory, which may serve as a new therapeutic target in the treatment of fear-related disorders.

Alterations of membrane properties and effects of D-serine on NMDA-induced current in rat anterior cingulate cortex neurons after monoarthritis.

Accumulated evidence implicates the anterior cingulate cortex (ACC) in pain processing. The activation of the NMDA receptor requires the occupation of both the glutamate site and the glycine site. d-Serine released by astrocytes is presumed to be an endogenous ligand for the glycine site of the NMDA receptor. Using whole-cell patch clamp recording, membrane characteristics and effects of exogenous d-serine on NMDA-evoked currents were examined in neurons in ACC slices from normal and complete Freund's adjuvant-induced monoarthritic rats. Neurons from rats with monoarthritis exhibited more depolarized membrane potential, lower firing threshold, lower input resistance and higher slope conductance compared with normal rats. The NMDA-evoked currents were enhanced by d-serine (20 microM) in both normal (135.3+/-4.3% of control, p < 0.01) and arthritic (157.9 +/- 9.7% of control, p < 0.01) rats, respectively. The effect of d-serine was greater in arthritic rats than control rats (p < 0.05). These results suggest that inflammatory pain increased the excitability of ACC neurons, and that the NMDA receptor glycine sites in the ACC neurons were not saturated in either normal or inflammatory pain states.

[Vascularized pedicle iliac crest for the repair of bone and soft tissue defect of lower extremity].

OBJECTIVE: To study the role of transplantation of the vascularized pedicle iliac crest for the repair of bone and soft tissue defect of lower extremity. METHODS: The vascularized pedicle iliac crest was designed for the repair of bone and soft tissue defect of lower extremity according to anatomic feature of leg and foot. Skin graft was used for coverage of the iliac flap. RESULTS: Skin survival could demonstrate the survival of the vascularized pedicle iliac crest indirectly one week postoperatively. Skin survived completely in 4 cases and partly in 3 cases. Callus was seen at the transplantation site one month postoperatively, and K-wires were removed 4 months later in the cases of metatarsal defect. The external fixators were removed in the cases of tibia defect 6 to 8 months postoperatively. The functions of lower extremities were restored in 2 to 4 months. The bone and soft tissue defects were repaired, and ultimate function and cosmetic effects were satisfied after the mean follow up of 10 months (ranged from 6 to 15 months). CONCLUSION: Transplantation of the vascularized pedicle iliac crest is an ideal method for the repair of bone and soft tissue defect of lower extremity. The operation can be performed in one stage. The functions and cosmetic effects are better than the traditional methods.

[The protective effects of melatonin on global cerebral ischemia-reperfusion injury in gerbils].

AIM: To investigate the effects of melatonin (MT) on histology and behavioral tests during global cerebral ischemia-reperfusion in gerbils. METHODS: Global cerebral ischemia was induced by occluding the bilateral common carotid arteries for 10 min in gerbils. Three doses of MT were administrated intraperitoneally 30 min prior to the onset of ischemia. Locomotor activity was measured by using the open field method 3 and 7 days after the ischemic episode. T maze test was carried out 4, 5 and 6 days after ischemia to assess the working memory of gerbils. Neuronal damage was assessed in CA1 pyramidal layer of gerbil hippocampus and evaluated 7 days after ischemia. RESULTS: MT significantly reversed the locomotor activity increases, ameliorated learning and working memory deficit, and reduced the extent of CA1 hippocampal pyramidal cells injury after transient global cerebral ischemia in the Mongolian gerbil. CONCLUSION: MT provides significantly protective effect against both histological and behavioral consequences of global cerebral ischemia-reperfusion injury in gerbils.

Using Greedy algorithm: DBSCAN revisited II.

The density-based clustering algorithm presented is different from the classical Density-Based Spatial Clustering of Applications with Noise (DBSCAN) (Ester et al., 1996), and has the following advantages: first, Greedy algorithm substitutes for R(*)-tree (Bechmann et al., 1990) in DBSCAN to index the clustering space so that the clustering time cost is decreased to great extent and I/O memory load is reduced as well; second, the merging condition to approach to arbitrary-shaped clusters is designed carefully so that a single threshold can distinguish correctly all clusters in a large spatial dataset though some density-skewed clusters live in it. Finally, authors investigate a robotic navigation and test two artificial datasets by the proposed algorithm to verify its effectiveness and efficiency.